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package org.apache.impala.planner;

import java.util.Set;

/**
 * Shared interface for all tuple cache placement policies.
 */
public interface TupleCachePlacementPolicy {

  /**
   * Given a set of eligible locations, return a set of locations that should actually
   * be used. The return set must be a subset of the eligible locations passed in.
   */
  public Set<PlanNode> getFinalCachingLocations(Set<PlanNode> eligibleLocations);
}
